Moisture Sorption Characteristics of Model Food Powders

Abstract

The purpose of this research was to provide fundamental data required for the process design of conveying, storage and processing of food powders. Potato starch, corn starch, wheat protein, soybean protein, and model food powders prepared by mixing potato starch and wheat protein were selected and their sorption characteristics such as equilibrium moisture content, monolayer moisture content, and sorption enthalpy were determined. Equilibrium moisture content and monolayer moisture content of high starch powders were higher than those of high protein powders, and the equilibrium moisture content decreased with temperature. The determination coefficients of the regression equations to predict the equilibrium moisture content of food powders were from 0.997 to 0.999. Sorption enthalpy experiments indicated that powder of high moisture content showed lower sorption than that of low· moisture content, and the high protein powder showed lower sorption than high starch powder.